Telephone-switchboard.



No. 732,931. 4 PATENTED JULY 7, 1903. G. E. EGAN. V TELEPHONE SWITGHBOARD.

APPLICATION FILED MAY 1. 1897. RENEWED JUNE 6. 1899.

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'No. 732,931. PATENTBD JULY v, 1903.

O.E.EGAN.

TELEPHONE SWITGHBOARD. APPLIOATION FILED MAY 1. 1897. RENEWED JUNE 6. 1899.

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- PATENT Patented July 7, 1903.

OFFICE.

CHARLES E. EGAN, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO WESTERN TELEPHONE MANUFAOTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHON E-SWITCHBOAR D.

SPECIFICATION forming part of Letters Patent N 0. 732,931, dated July '7, 1903. Application filed May 1,1897. Renewed June 5, 1899. Serial No. 719,418. (No model.)

. To all whom zit may concern.-

Be it known that I, CHARLES E. EGA acitizen of the United States, residing in Ohicago, in the countyof Cook and State of Illi-' nois, have invented a new and useful Improvement in Telephone-Switchboards, of which a the following is a specification.

This invention is designed to render the switchboard very compact and to furnish an exceedinglypracticable construction which shall also tend to lessen the liability to mistakes on thepart of the operator.

In the drawings, Figure 1 is a section of the board in connection with a diagram of the circuits. Fig. 2 is an enlarged section, and Fig. Bis an enlarged front view of one of the jacks and its drop.

In said drawings, AA represent a series of metal sockets or jacks secured in the front A They are secured in place by screws A passing through the front of the board, and each is adapted to receive one of the plugs B, attached to the flexible conductor B and serving to connect the subscribers in the usual manner. f At opposite sides of each jack and in such proximity thereto as to enablethe attendant to operate supported in the, rear upright A them with the same hand whereby she inserts I the plug into the jack are movable arms 0 and D, preferably of spring metal and both capable of slight movement. All the arms are The arms O are moved against the contact-pieces G,

which are in circuit with the jacks, and the arms D are normally in contact with contactpieces D and are movable away therefrom and into contact with contact-piece D The drops E are located at their correspon ding jacks, preferably as seen at Figs. 2 and 3.

In order to economize the surface room required by this feature of construction, I prefer to cut an opening or slot E in each drop large enough to enable the drops to set over the jacks I also prefer to hinge the drops to the board, as shown at E The magnets E for releasing the drops are located in the rear of the frontA and preferably directly back of the respective jacks to which the drops belong.

I also prefer to make the cores of the at Fig. 2.' The catch-levers E, which hold the drops in their normal positions, are secured in the swinging armatures E of the magnets and project over or through the board-front A, as shown.

The electric circuits may be substantially as indicated at Fig. 1. The primary circuit F includes battery F, transmitter F and induction-coil F secondary circuit G including said induction-coil and receiver G", which is kept at the operators car at the central station, as usual. The secondary circuit is connected, to each arm 0 by branch wires G and also to the common return-Wire or to the ground. J is the call-generator circuit, also connected to the return wire H, and includes the electromagnetic generator J. It is also connected to each contact-point D by wires J The telephones shown at K K are connected to return-wire H by branch wires H and to the arms D of their respective jacks by wires K K. Each jack is also connected to its corresponding telephone-wire K by a wire L, leading to the rear end of arm D. The dropmagnets are connected upon one side to the contacts D by Wires E and upon the other side bybranch E and wire E connecting with the circuit-wire H. The circuits above set forth, with the single exception of the one operating the drop, are fully described by me in my application filed December 5, 1896, as Serial No. 614,530, as are also the construction of the jack and themovable arms and their mode of operation, and those features form 110 part of the present invention.

The drop-magnets are each covered with casingsof magnetic metal, such as iron or steel, in order to break up the lines of force and prevent induced currents therein. This magnetic armor may be and preferably is formed by closely coiling Wire around the magnet, as shown at M. I find that by the use of this armor upon the drop-magnets board, of a drop-magnet located behind the board and directly in line with the jack, said magnet being provided with a Vulcanizedfiber core, a drop, and a screw adapted to connect the core to attach the magnet to the board. I

3. In combination with the jack projecting in front of the board, a drop-magnet having an insulating-core and located back of the board and directly in line with the jack, a drop, and a single screw acting to secure both the jack and the magnet to the board, substantially as specified.

CHARLES E. EGAN.

Witnesses:

H. M. MUNDAY, EDW. S. EVARTS. 

